This article discusses the differences between ozone in the stratosphere and troposphere, and how NASA is measuring ozone using a spectrometer on-board the Aura satellite. The article includes an activity: building a spectroscope using a DVD cover...(View More) and inexpensive materials.(View Less)

This article discusses how Global Positioning System (GPS) satellites work, and how the TOPEX and Jason-1 satellites use GPS data in making very precise topological maps of the oceans. The article includes an activity. Students are divided into two...(View More) groups. One group will use triangulation to record the positions of several objects placed in a room. Using measurements from this first group, the second group will try to determine the exact placement of the objects in the first room and recreate the pattern in the second room.(View Less)